1. Field of the Invention
The present invention relates to a data communication system, apparatus, and method, and more particularly, to a technique of communication of data via a digital interface.
2. Description of the Related Art
It has been the conventional practice to connect peripheral equipment such as a hard disk or a printer to a personal computer (hereinafter referred to as xe2x80x9cPCxe2x80x9d) via a digital interface (hereinafter referred to as xe2x80x9cI/Fxe2x80x9d) such as an SCSI or an IDE, thereby conducting communication of digital information data with PC.
AV (audio-visual) devices such as a digital camera and a digital video camera so far not falling under peripheral equipment of a PC have now serve as input units to the PC as a result of progress made in this area. Various techniques are being developed for such input units, for example, entering moving images or a still image taken by any of these devices into a PC, processing and editing the image on the PC, and storing the resultant image in a hard disk or printing it out on a printer.
However, it has been difficult to send in a real-time manner digital data in a large quantity such as animation images from a digital video camera to a PC through a digital I/F such as an SCSI conventionally used for a hard disk or a printer, because of a low data transfer rate. Further, the conventional digital I/F, based on parallel communication, have large connectors and cables, are not suitable for an interface for a portable device requiring downsizing such as a digital camera and a digital video camera. In the conventional digital I/F, inconveniences have been pointed out in many aspects, including limitations of the connecting method, and complicated setting upon connecting. AV devices such as a digital camera and a digital video camera have therefore been connected to a PC via a digital I/F based on a technique different from that of the digital I/F such as an SCSI.
In a network in which a PC is connected to peripheral equipment and an AV device, when image information of the AV device is printed out, it has been necessary first to transfer image information via a digital I/F different from the conventional one, and further, to output from the PC to a printer via a conventional I/F. As a result, the AV device transmitting data in a large quantity to the PC poses a considerable load on the PC itself, and causes the network to be seriously crowded. Depending upon operation of the PC, it is affected by communication between other devices on the network, thus leading to a problem of making it impossible to normally print out the image information of the AV device.
An object of the present invention is to solve the above-described problems.
Another object of the invention is to achieve rapid data communication, in a data communication apparatus, with a prescribed device without applying a large load on the network.
As a preferred embodiment for such objects, the invention provides a data communication apparatus, comprising (a) first and second connecting means for connecting said apparatus to respective first and second external devices through respective first and second transmission lines, said first and second transmission lines transmitting digital data; (b) communication means for communications with the external device connected to said first or second connecting means; (c) detecting means which detects connection of the second external device to said second connecting means; and (d) control means for giving priority to communication between said communication means and the second external device connected to said second connecting means in response to the detection of said detecting means.
As another embodiment, the invention provides a data communication apparatus comprising (a) a first port connectable to a first data bus; (b) a second port connectable to a second data bus; (c) communication means for performing data communication with one of said first and second data buses through the corresponding first or second port; and (d) control means for causing a re-configuration of said first data bus in response to a connection of said second port to said second data bus.
As another embodiment, the invention provides a data communication apparatus, comprising (a) first and second communication means respectively communicable with first and second external devices; (b) power supply means which supplies power to said first and second communication means; (c) detecting means which detects a connection between said second communication means and the second external device; and (d) control means which controls said power supply means so as to change the power supplied to said first and second communication means in response to the detection of said detecting means.
As another embodiment, the invention provides a data communication apparatus, comprising (a) first communication means communicable with a first data bus; (b) second communication means communicable with a second data bus; (c) detecting means which detects the connection of an external device to said second communication means; and (d) control means which causes said first communication means to discontinue communication with said first data bus in response to the detection of said detecting means.
Another object of the invention is to achieve rapid data communication, in a data communication method, with a prescribed device without applying a large load on the network.
As a preferred embodiment for such an object, the invention provides a data communication system, comprising (a) first and second connecting means for connecting said apparatus to respective first and second external devices through respective first and second transmission lines, said first and second transmission lines transmitting digital data; (b) communication means for communicating with the external device which is currently connected to said first or second connecting means; (c) detecting means which detects the connection of the second external device to said second connecting means; and (d) control means which gives priority to communication between the communication means and the second external device connected to said second connecting means when said detecting means detects connection of said second external device to said second connecting means.
As another embodiment, the invention provides a data communication system, comprising (a) a first port connectable to a first data bus; (b) a second port connectable to a second data bus; (c) communication means for performing data communication with one of the first and second data buses through one of said first and second ports identified as being valid; and (d) control means for causing said first data bus to recognize data bus configuration in response to the connection of said second port to said second data bus.
As another embodiment, the invention provides a data communication system, comprising (a) first and second communication means respectively communicable with first and second external devices; (b) power supply means for supplying power to said first and second communication means; (c) detecting means which detects the connection of said second communication means to the second external device; and (d) control means which controls said power supply means so as to change power supplied to said first and second communication means in response to said detecting means detecting the connection of said second communication means to the second external device.
As a further embodiment, the invention provides a data communication system, comprising (a) first communication means communicable with a first data bus; (b) second communication means communicable with a second data bus; (c) detecting means which detects the connection of an external device to said second connecting means; and (d) control means which controls said first communication means so as to discontinue communication with said first data bus in response to said detecting means detecting the connection of the external device to said second connecting means.
Another object of the invention is to achieve rapid data communication, in a data communication system, with a prescribed device without applying a large load on the network.
As a preferred embodiment for such an object, the invention provides a method of data communication, comprising the steps of: (a) providing first and second communication interfaces for communicating with respective first and second external devices over respective first and second transmission lines, said first and second transmission lines transmitting digital data; (b) detecting a connection of the second external device to said second interface; and (c) giving priority to communication with the second external device connected to said second interface in response to the result of detection obtained from said detecting step.
As another embodiment, the invention provides a method of data communication, comprising (a) a setting step of selecting as valid one of a first port connectable to a first data bus and a second port connectable to a second data bus; (b) a communicating step of conducting data communication via the first or second data bus selected as valid in said setting step; and (c) a control step of causing said first data bus to recognize a new bus configuration in response to a connection of said second port to the second data bus.
As another embodiment, the invention provides a method of data communication, comprising (a) a power supplying step of supplying power to first and second digital interfaces communicable with respective first and second external devices; (b) a detecting step of detecting a connection of said second digital interface to the second external device; and (c) a control step of changing power supplied to said first and second digital interfaces in response to the detection obtained from said detecting step.
As a further embodiment, the invention provides a method of data communication, comprising (a) a communicating step of conducting communication with a first data bus via a first digital interface; (b) a detecting step of detecting the connection of an external device to a second digital interface communicable with a second data bus; and (c) a control step of controlling said first digital interface so as to discontinue communication with said first data bus in response to the result of detection obtained from said detecting step.
Still other objects of the present invention, and the advantages thereof, will become fully apparent from the following detailed description of the embodiments.